Husqvarna 343R, 345RX, 343F, 345FX, 345FXT Brush Cutter User Manual
Contents
1. 26 NOTE A tachometer should always be used to find the optimal setting The recommended max speed must not be exceeded Idling speed T screw Let the engine idle for about 30 seconds or until the speed has stabilised Adjust the idling speed T screw until the engine idles without stopping Turn the screw clockwise if the engine stops e Turn the screw anticlockwise to lower the speed Correctly adjusted carburettor A correctly adjusted carburettor means that the engine accelerates without hesitation and it splatters a little at full throttle e Atoo lean adjusted L needle can cause starting difficulties and poor acceleration e Atoo lean adjusted H needle results in lower power poor acceleration and or damage to the engine e A too rich setting of the L and H needles give accelera tion problems or a too low working speed NOTE If the cutting equipment rotates while idling the T screw should be turned anticlockwise until it stops Carburettors in E Tech and CARB EPA designs CARB II EPA II only applies to USA and Canada On these types of carburettor the H and L needles can be adjusted within ex tremely tight limits to among other things comply with the stringent demands with regard to the hydrocarbon and nitrogen oxide content in the exhaust fumes The carburettor needles on these carburettors are fitted with plastic sleeves with movement limiters so called caps To carr2. 4 Husqvarna Workshop manual 343R 345RX 343F 345FX 345FXT Workshop Manual Brushcutter Trimmer Model 343R 345RX 343F 345FX 345FXT Contents General recommendations 2 1 Starter 3 2 Electrical system 7 3 Fuel system 15 4 Centrifugal clutch 31 37 5 Angle gear 6 Cylinder and piston 7 Crankshaft and crankcase 51 8 Tools 4 Husqvarna Copyright Husqvarna AB Sweden 2003 General recommendations Remember A Never start the engine without the clutch and clutch drum mounted N Do not grasp hot elements such as the muffler or the clutch before they have cooled sufficiently to avoid burn injuries A Avoid getting petrol on you skin or in your mouth Use protective cream on your hands This lowers the risk of infection and makes dirt easier to wash off Long term contact with engine oil can be damaging to your health A Never run the engine indoors The engine exhaust is poisonous N Wipe up any spilled oil from the floor immediately in order to avoid injuries from slipping N Do not use tools that are worn or fit poorly on nuts and bolts and so on Always work on a clean work surface Always work in a logical manner in order to be sure that all components are correctly attached and that nuts and bolts are tightened Use special tools where recommended in order to work correctly Fire risk Handle petrol with respect since it is highly flammable Do not smoke and ensure
3. Still no spark Check the spark plug connection Remove the spark plug cover and make sure the ignition cable is not damaged Remove a segment of cable if required to get sufficient contact at the connec tion coll Still no spark Check other cables and connections for poor contacts dirt corrosion cable breakage and damaged insulation Make sure that the cables are correctly drawn and lie in the cable grooves Do not forget to check the cables in the throttle too See chapter 3 Throttle Tip Use an Ohmmeter in order to easily check if cable breakage has occurred due to pinching for example Electrical system Still no spark Check the air gap 502 51 34 02 Adjust the air gap Replacing the spark plug cover 1 Insert the ignition cable through the spark plug cover 2 Make a hole in the ignition cable for the ignition coll 502 50 06 01 3 Attach the ignition coil to the ignition cable NOTE Still no spark Check the air gap between the flywheel magnet and the ignition module The gap should be 0 3 mm Use a 502 51 34 02 feeler gauge Adjust the air gap as needed to the correct value e Loosen the bolts Position the feeler gauge and press the ignition module against the flywheel e Tighten the bolts and check the air gap again If the spark plug still does not fire the ignition system should be replaced Replacing the spark plug cover 1
4. 502 50 30 19 Crankshaft and crankcase 7 Check that the there is no play in the fill out plates around the crank disks applies to models F F _ R X XT Assembly Heat the crankcase halves to approx 150 C using a hot air gun and position the bearings Make sure they go right down into the bearing seats Lubricate the big end bearing with a few drops of engine oil and position the crankshaft in the clutch side crankcase half Pull the crankshaft into place with tool no 502 50 30 19 Make sure that the connecting rod is not squeezed against the crankcase Fit a new gasket to the clutch side crankcase half Place the other crankcase half over the crankshaft and place the 4 crankcase bolts so that they guide the gasket Pull the crankcase half into place with tool no 502 50 30 19 Tighten the crankcase bolts Check that the crankshaft can rotate easily If not hit the axle spindles sharply a few times with a rubber hammer so that the tension in the crankshaft disappears 55 7 Crankshaft and crankcase Fit the sealing rings 505 38 17 09 3 Piston and cylinder NOTE This would result in poor idling 6 Flywheel 7 Ignition module o u 10 Clutch 11 Shaft Leakage testing the crankcase Fit the two sealing plates A and the pressure test nipple B x 502 54 11 02 503 84 40 01 56 Lubricate the axle spindles with engine oil
5. 500 rom cannot be exceeded even if the H needle is screwed inwards The risk in this case is still that the engine breaks down as a result of a too lean fuel air mix e At full throttle the H needle shall have a setting so that the engine is almost splutters 25 3 Fuel system When checking the speed on a trimmer no part of the cord should be extended Use the 502 71 14 01 tachom eter to check the speed e Carefully screw in clock wise the L and H jets until they bottom Now screw out anticlockwise the needles 1 turn The carburettor now has the setting H 1 and L 1 Use special screwdriver 501 60 02 03 502 71 14 01 501 60 02 03 e Start the engine and run warm for 10 minutes Low speed jet L Find the highest idling speed by slowly turning the low speed needle clockwise and anticlockwise When the highest speed has been found turn the L needle 1 4 turn anticlockwise High speed jet H The high speed H needle affects the engine s power and speed A too lean H needle setting H needle screwed in too far gives too little fuel to the engine resulting in damage to the engine Run the engine at full throttle for about 10 seconds The H needle is set correctly when the engine splatters a little If the muffler smokes heavily at the same time as the engine splatters a great deal the setting is too rich Turn the H needle clockwise until you find the setting that sounds right
6. C and lever arm D if necessary Check that the cables are properly pressed into the cut outs E and that the throttle cable F is in the right groove If necessary attach it with silicon adhesive in order to facilitate assembly Check that the protective bellows G are whole and that they are correctly mounted over the ball on the cable Remove the bolt A that attaches the throttle to the handle Be careful not to lose the nut Remove the throttle and remove bolts B and C Carefully separate the two halves of the throttle Fuel system 1 LD A ala H E Y CF 3 Disassemble the throttle control A the lock to prevent accidental throttle operation B the start throttle lock C and the throttle stop D in order to check if replacement is necessary The stop switch can also be disassem bled now and replaced if necessary Use a screwdriver to press the stop switch s wing locks E Tip Reassembly of the throttle easier if a thin steel wire is wrapped around the handle and bolt F in order to hold the throttle cable and short circuit cables in place 29 30 Centrifugal clutch Contents Dismantling 30 Assembly 32 Clutch drum 32 4 Centrifugal clutch The centrifugal clutch has the task of transferring the Some slipping occurs between the clutch and the power from the engine to the cutting equipment s drive clutch drum when accelerating as well as in the axle A
7. Check the circlips If they exhibit cracks or are discoloured caused by overheating they must be replaced Assembly Assembly Lubricate the gudgeon pin s needle Lubricate the gudgeon pin s needle bearing with a few drops of engine oil bearing with a few drops of engine oil and fit the piston Direct the arrow on the top of the piston towards the exhaust port Press in the gudgeon pin and fit the circlips NOTE Place a rag in the crankcase opening to prevent the circlip from falling into the crankcase in case it should fly out Check that the circlips are correctly fitted into the grooves by turning the clips with long nosed pliers 44 Cylinder and piston 6 Use a new gasket and fit the cylinder Place a new cylinder pedestal gasket Make sure that the inlet manifold is on the cylinder correctly connected to the sleeve Lubricate the piston and the inlet coupling on the cylinder and that the manifold on the cylinder with a few impulse nipple sits right drops of engine oil and fit the cylinder using the smallest piston ring compres sor in assembly kit 502 50 70 01 Make sure that the inlet manifold is correctly connected to the sleeve coupling on the cylinder and that the N impulse nipple sits right aa 4 502 50 70 01 Screw the cylinder into place and Screw the cylinder into place tighten the clamp around the inlet Tighten the clamp around the inlet manifold manifold Assemble the ot
8. clean it from soot deposits with the help of a steel brush Check the electrode gap It should be 0 5 mm Adjust the gap as needed to the correct value with the side electrode If the electrodes are worn more than 50 the spark plug should be changed Too large a spark gap entails a great deal of stress on the ignition module and risk for short circuiting Also check that the stop switch is in the start position Earth the spark plug on the cylinder and pull sharply on the start handle A spark should be seen between the electrodes If no spark is seen test with test spark plug no 502 71 13 01 If a spark then occurs the spark plug is faulty Try a new spark plug Electrical system If no spark occurs disconnect the stop switch Replace the switch if necessary The stop switch can be easily detached with a screwdriver Still no spark Check the ignition cable s connection to the spark plug cover Still no spark Check other cables and connections 2 If no spark occurs even now remove the short circuit cable from the connec tion point in the carburettor compart ment If the plug now sparks the fault is either in the stop switch or the short circuit cable Change the switch as needed and check to see if the cable insulation is damaged The stop switch is easily reached when the cover is removed Use a screwdriver pinch the switch s snap fastener inside the throttle
9. lining against the valve head when grinding Fit the decompression valve in the cylinder 43 6 Cylinder and piston Inlet manifold Remove the air filter and carburettor Remove the inlet manifold A from the partition B Check that it does not exhibit cracks or other damage that can cause leaks between the carburettor and cylinder If necessary fit a new inlet manifold in the reverse order as set out for dismantling NOTE Exercise caution if the inlet manifold is fitted using a screwdriver so as not to make any holes in the rubber wall Cleaning inspection After dismantling clean the individual components 1 Scrape carbon deposits from the top of the piston 2 Scrape carbon deposits from the cylinder s combustion chamber 3 Scrape carbon deposits from the cylinder s exhaust port NOTE Scrape carefully with not too sharp a tool so as not to damage the soft aluminium parts 4 Wash all the components 5 Inspect the different components for damage and wear Check the piston and cylinder for seizure damage and wear Also see the Analysis and actions section Check the piston ring for wear and damage Also see the Analysis and actions section Check the gudgeon pin Ifit has blued it must be replaced Ifthe piston moves too easily both the piston and the gudgeon pin must be replaced Check the needle bearing If it is discoloured or damaged it must be replaced
10. of the cylinder ment ment 50 Crankshaft and crankcase Contents Dismantling 52 Inspecting the crankshaft 54 Assembly 55 Leakage testing the crankcase 56 7 Crankshaft and crankcase The task of the crankshaft is to transform the reciprocating The crankshaft is journalled in the crankcase on motion of the piston to rotation This requires a stable heavy duty ball bearings In addition to the journalling design withstanding immense pressure and rotational and point for the crankshaft the crankcase acts as a bending strain as well as high rotational speed In addition scavenging pump for the fuel air mixture when this Is the connecting rod is exposed to large acceleration and sucked from the carburettor and is forced into the retardation forces as it moves between the top and bottom cylinder s combustion chamber The crankcase must dead centres This puts special demands on the bearings be perfectly sealed so as not to affect this pump that must withstand quick changes in load Moreover the function There cannot be any leakage from the crank bearing s roller retainer must also cope with high tempera shaft between the crankcase halves or between the tures and friction It is therefore extremely important when crankcase and the cylinder servicing to check the roller retainer for cracks wear and Always replace the sealing rings and gaskets when discolouration caused by overheating servicing the crankcase
11. that there are no open flames or sparks in the vicinity Make sure that there is a functioning fire extinguisher in the vicinity Do not try to extinguish a petrol fire with water Poisonous fumes When using cleaning fluids read the instructions carefully Make sure that ventilation is good when handling petrol trichlo roethylene and other highly volatile liquids The engine exhaust is poisonous Test run the engine only if ventilation is good Preferably outside WARNING Risk of personal injury if the instructions are not followed Special tools Certain tasks in this handbook require the use of special tools In sections where this is applicable an image of the tool with an ordering number is provided We recommend using special tools in order to avoid personal injury and to eliminate expensive damage to the components in question 502 51 03 01 Sealing faces and gaskets Make sure that all sealing faces are clean and free from old gasket remnants Use a tool that will not damage the sealing face when it is cleaned Any scratches and irregularities should be removed with a fine float cut file Sealing rings Always change a sealing ring once it has been dismounted The sensitive sealing lips can be easily damaged with poor sealing ability as a result The surfaces that the seal is to tighten against must also be completely free from damage Lubricate the sealing lip with grease before it is attached and make
12. the crankcase Max permitted leakage 20 kPa 0 2 kp cm per 30 seconds Connect meter 531 03 06 23 to the nipple and lower the pressure in the crankcase to 50 kPa 0 5 kp cm Max permitted leakage 20 kPa 0 2 kp cm per 30 seconds Any leakage can be difficult to localise if the crankcase is depressurised When leakage has been established with a vacuum you can apply a slight overpressure 0 1 0 3 kp cm and at the same time apply a layer of thin oil to the joints and the sealing ring contact surfaces on the crankcase to make leak detection easier Bubbles clearly mark the position of the leakage 531 03 06 23 503 55 22 01 Fuel consisting of Exhaust gases Hydrocarbons petrol consisting of Two stroke oil 2 Hydrocarbon HC Air consisting of 21 oxygen 78 nitrogen 1 other Sl Fuel air mixture consisting of 92 air 8 petrol Nitrous oxide NO Carbon monoxide CO Carbon dioxide CO Particles PM ov Adjustable fuel jets with movement limiters Husqvarna E Tech In 1996 Husqvarna presented a new improved two stroke engine as a part of the company s efforts to produce engines that emit smaller amounts of hazardous substances The new engine was given the desig nation E Tech and was first used in a new brush cutter model More stringent environment regulations in the USA which primarily involve a lowering of the hydrocarbons nitrous oxides and carbo
13. 42 Cylinder and piston Dismantle the piston 502 52 42 01 Decompression valve Dismantle the decompression valve Check that the non return valve A is tight under a vacuum of 50 kPa Otherwise replace the valve NOTE Turn the valve the right way when fitting x A VASI IEF NES 531 03 06 23 Clean the decompression valve and check that the valve head is not dam aged burnt and that the valve oper ates easily If necessary grind the valve with fine grained valve grinding compound 6 Push the gudgeon pin from the piston using punch 502 52 42 01 If the pin is too tight carefully warm the piston Decompression valve Remove the bolt A and the hose B that connect the decompression valve to the nipple on the cylinder Unscrew the valve from the cylinder Inside the rubber sleeve on the nipple in the cylinder is a non return valve A Check with pressure gauge 531 03 06 23 Pump up a vacuum of 50 kPa The valve must be fully tight Otherwise replace the valve NOTE When the valve is fitted the small hole must face outwards Clean the decompression valve with white spirit or thinner and blow dry with compressed air Check that the valve moves easily in the guide and that the valve head is not damaged burnt If necessary grind the valve into the seat using fine grained valve grinding compound Tip Use washer no 502 54 11 01 asa friction
14. 52 42 01 502 50 70 01 503 80 17 01 502 50 18 01 502 50 30 19 502 54 11 02 503 84 40 01 CI S X NN WY CN CE AN Y7 O ij Husavarna www husqvarna com 114 01 98 26 2003W24
15. 97 64 01 39 Angle gear 40 Shaft The shaft contains a drive axle guide that is easily replaced It can be dismantled once the plastic sleeve B has been removed Centre the axle control in the shaft when a new one is fitted Fit a new O ring to ensure a good seal 503 80 17 01 Shaft The shaft contains a long plastic guide to prevent vibrations in the drive axle The guide A is easily removed for replacement Bend away the plastic sleeve B and the O ring C using a knife and pull the drive axle guide out from the shaft When replacing the axle guide the replacement must be inserted into the shaft so that the distance is the same to the two ends of the shaft When fitting a new O ring must be used To avoid damage from the sharp edges of the slits in the gearbox the following assembly procedure is recommended 1 Placethe plastic sleeve B in position in the gearbox 2 Slide the O ring C onto the plastic sleeve 3 Slide the shaft and guide A into position Lubricate the drive axle with grease no 503 80 17 01 when assembling Cylinder and piston Contents Dismantling Decompression valve Inlet manifold Cleaning inspection Assembly Analysis and actions Service tips Wear tolerances 42 43 44 44 44 45 49 50 41 6 Cylinder and piston The cylinder and the piston are two of the compo When servicing these components cleanliness is of nen
16. Assembly Clean requisite parts and assemble in Clean all components before assembly the reverse order as set out for disman Change return springs starter pulley tling and starter cord as needed NOTE Be careful when opening the packaging with the return spring so that the spring does not fly out Attach the spring cassette Attach the spring cassette and tighten Attach the starter pulley the two bolts A Attach the new starter cord Lubricate the bearing journal with a little grease and attach the starter pulley Place the washer in place and tighten the bolt Attach the new starter cord Push it in to the starter pulley s track as illustrated and then out through the cord guide in the starter cover Make sure that the knot at the end of the cord is as small as possible NOTE New starter cords can be attached without dismantling the starter Anchor the cord in the starter handle Thread the cord through the starter handle and anchor it with a knot Fold down the free end and pull the knot well into the handle 6 Starter Tighten the return spring Check the spring tension Mount the starter onto the engine Replacing the drive dogs See chapter 2 Ignition system Tighten the return spring Lift up the starter cord when the return spring is completely loose and the cord pulled out completely Then turn the starter pulley anti clockwise 7 revolutions Check the spring
17. Dismantling Dismantling Dismantle all components so that only Dismantle all components so that only the crankcase and crankshaft remain the crankcase and crankshaft remain Dismantle the guard under the crank See the respective sections for detailed case information if necessary Remove the 4 bolts and lift off the guard from under the crankcase Bend away the heat guard A and Bend away the heat guard A with your cable guide B fingers and carefully push the cable guide B aside with a screwdriver Remove the 4 bolts holding the crank Remove the 4 bolts holding the crank case halves together case halves together 502 50 18 01 52 Crankshaft and crankcase 7 Separate the crankcase halves X m 7 J LY Push out the crankshaft from the crankcase half Remove the bearing and sealing rings from the crankcase halves 505 38 17 09 Fit tool 502 52 39 01 to the clutch side of the crankcase as illustrated Separate the crankcase halves Fit tool 502 52 39 01 as illustrated Push out the crankshaft from the crankcase half Heat the crankcase halves to approx 150 C using a hot air gun Knock the halves against a wooden block so that the bearings fall out of their seats Remove the gaskets with a suitable punch 53 7 Crankshaft and crankcase 54 Inspecting the crankshaft Inspect the large end of the connecting rod Inspect the small end of the connecting ro
18. Flock material becomes loose and holes appear e Air filter incorrectly fitted e Air filter damaged or missing Action Fit a finer grade filter Check the filter carefully for holes and damage after cleaning Replace the filter if necessary Clean more carefully and use the right cleaning agent Such as tepid soapy water Change the filter Fit the filter correctly Fit a new air filter Larger softer particles that penetrate into the engine cause damage to the piston skirt under the piston ring as the illustration shows Cause e Air filter incorrectly fitted e Air filter damaged or missing Action Fit the air filter correctly Fit a new air filter Cylinder and piston 6 Larger harder particles that enter the engine cause serious damage to the under side of the piston skirt Cause Action e Air filter damaged or missing Fit a new air filter e Parts from the carburettor or intake Regular service and inspection system have come loose and entered the engine Extensive damage to the lower part of the piston s inlet side Service tips Defect Action Broken cooling fins damaged threads or sheared bolts by In severe cases replace the cylinder the exhaust port Repair the threads using Heli Coil Seizure marks in the cylinder bore especially by the Polish the damaged area using a fine grade emery cloth exhaust port so that the coating of aluminium disa
19. Lubricate the ignition cable with a little grease and thread it through the spark plug cover 2 Cut off a bit of the ignition cable approx 5 mm and make a hole in the cable for the ignition coil with the aid of a pair of no 502 50 06 01 pliers 3 Attach the ignition coil to the ignition cable and ensure that the wire is folded along the cable 4 Pull the ignition coil into the spark plug cover It is important that the tip of the ignition coil hits the centre of the ignition cable to prevent sparking Leo NQ N a y 2 1 SA URS Electrical system Dismantling Remove the starter cylinder cover and spark plug Attach piston stop no 502 54 15 01 502 54 15 01 Remove the nut holding the flywheel Remove the flywheel 502 51 94 01 Remove the ignition module and the generator 502 50 18 01 2 Dismantling Remove the starter cylinder cover and spark plug Fit piston stop no 502 54 15 01 in the spark plug hole NOTE Place the piston stop so it is caught between the piston and the cylinder head Not so it sticks out into the exhaust port Remove the nut holding the flywheel Remove the flywheel from the crank shaft using punch no 502 51 94 01 Leave a gap of approx 2 mm between the punch and the flywheel Gently knock the punch with a hammer while holding the flywheel with your other hand Dismantle the ignition module Remove the ignition cabl
20. ad from the outside Replace the fuel screen if it is damaged or cannot be cleaned Place the pump diaphragm closest to the carburettor housing Then the gasket and cover and the other compo nents in reverse order of removal NOTE Check that the valves are turned correctly and that they close completely and tightly in the closed position Use Loctite on the valve screws 23 Fuel system 24 Attach the various parts of the measur ing unit in the reverse order as set out for dismantling Check that the carburettor is sealed No leakage is permitted at 50 kPa 531 03 06 23 Attach the control diaphragm and cover Assembly Slide the carburettor into place and connect the fuel hoses Make sure that they do not get pinched Connect the throttle cable to the carburettor Attach the various parts of the measur ing unit in the reverse order as set out for dismantling The lever arm should lie flush with the carburettor housing Too high setting too much fuel Too low setting too little fuel NOTE The H needle is a little shorter than the L needle Connect pressure tester 531 03 06 23 to the fuel intake on the carburettor Pump up the pressure to 50 kPa Lower the carburettor in a vessel with petrol in order to discover any leaks more easily No leakage is permitted Place the gasket on the carburettor housing and then the control dia phragm Check
21. and press the sealing rings until level with the crankcase using a suitable punch or tool 502 50 30 19 The metal covers of the sealing rings should face outwards Assemble the remaining parts in the following order 1 Cable guide and heat guard on the carburettor side of the crankcase 2 Protective grating on the underside of the crankcase A Partition on the carburettor side with attached inlet manifold If the inlet manifold has been removed no sharp implements may be used to replace it as there is a risk that holes will be made in the inlet manifold 5 Generator Make sure that the cable is pressed into the groove in the crankcase 9 Carburettor with fitted air filler holder and bushings for fuel hoses Leakage testing the crankcase Remove the throttle cable and air filter holder from the carburettor Fit a sealing plate A 502 54 11 02 between the carburettor and the distance piece and a plate between the cylinder and the heat guard plate by the muffler NOTE Press down the sealing plates as far as possible between the bolts to ensure a proper seal Fit the pressure test nipple B 503 84 40 01 in the spark plug hole Crankshaft and crankcase 7 Fit plug 503 55 22 01 instead of the Fit plug 503 55 22 01 instead of the decompression valve decompression valve Connect meter 531 03 06 23 and check Connect meter 531 03 06 23 to the for leakage nipple and pump up a pressure of 50 kPa 0 5 kp cm in
22. around the axle remain Angle gear 5 Remove the lubricant top up plug Remove the lubricant top up plug and Warm the gearbox and knock it against warm the entire gearbox using a hot air a wooden block so that the input axle gun to about 150 C falls out Knock the gearbox against awooden block so that the input axle and bearing fall out NOTE The input axle with pinion must be dismantled first Remove the output axle Then remove the output axle and bearings while the gearbox is still warm Use puller no 502 50 65 01 502 50 65 01 Assembly Replace damaged parts Assemble the angle gear in the reverse order as set out for dismantling Fit the bearings on their respective axles It is easier if the bearings are heated to approx 100 C NOTE Do not forget the circlip holding the bearing on the input axle Make sure the bearings bottom in their seats Heat the gearbox to approx 150 C and first lift the output axle in position and M j I then the input axle Make sure the bearings bottom in their seats Mount the circlips and make sure they lie correctly in their grooves Rotate the axles and check that they rotate easily without a tendency for the cogwheels to seize Fill the gearbox with special grease no 503 97 64 01 Wipe any excess grease from the joint between the shaft and the angle gear before the gear is fitted to prevent it from turning around the shaft 503
23. d Check the crank bearing Inspect the crankshaft bearing and sealing rings Inspecting the crankshaft The crankshaft cannot be reconditioned but must be replaced if it is worn or damaged Inspect the large end of the connecting rod If seizure marks discolouration on the sides or damaged needle holders are found the crankshaft must be replaced Inspect the small end of the connecting rod If seizure marks or discolouration are found in the bearing track the crank shaft must be replaced Check the crank bearing The connect ing rod shall not have any radial play up and down It should however have axial play in order to ensure good lubrication of the crank bearing among other things Check for wear in the crankshaft bearing and sealing rings Clean the bearings and rotate the outer ring If movement is jerky the bearing track is probably damaged If so replace the bearing Also check that the gap is not too great Inspect the sealing rings The seal edge shall be sharp or slightly ground Check that the there is no play in the fill out plates around the crank disks applies to models F F _ R XxX XT Assembly Mount the bearings in the crankcase halves First fit the crankshaft in the clutch side crankcase half 502 50 30 19 Fit a new gasket to the clutch side crankcase half Pull the other crankcase half into position and tighten the 4 crankcase bolts
24. d be tween the piston and cylinder wall damaging the piston skirt Debris can also pass up through the cylinder s transfer channels and cause damage to the top and sides of the piston as well as to the cylinder s combustion chamber 47 6 Cylinder and piston Small score marks and a matt grey surface on the piston s inlet side caused by fine dust particles Inlet side Particles of dust and dirt from carbon like deposits on the top of the piston and in the piston ring groove The piston ring sits firmly in the groove Piston material has been worn away The lower part of the piston skirt is thinner on the inlet side than on the exhaust side The piston scored and worn from the piston ring down on the inlet side 48 Foreign objects Everything other than clean air and pure fuel that enters the engine s inlet port causes some type of abnormal wear or damage to the cylinder and piston This type of increased wear shows on the piston s inlet side starting at the lower edge of the piston skirt The damage is caused by badly filtered air that passes through the carburettor and into the engine Cause e Faulty air filter Small dust particles pass through the filter e The filter is worn out due to too much cleaning whereby small holes have appeared in the material e Unsuitable filter maintenance such as wrong method or wrong cleaning agent
25. dity tempera ture and air pressure L Low speed needle H High speed needle T Idle adjustment screw The fuel quantity in relation to the air flow permitted by the throttle opening is adjusted by the L and H jets Turning the needles clockwise gives a leaner fuel mixture less fuel and turning them anticlockwise gives a richer fuel mixture more fuel A leaner mixture gives higher revs while a richer mixture gives less revs e The T screw regulates the position of the throttle while the engine is idling Turning the screw clockwise gives a higher idling speed while turning it anti clockwise gives a lower idling speed Basic setting The carburettor is set to its basic setting when test run at the factory The basic setting is richer than the optimal setting fast idle speed is 600 800 rpm under the recommended max speed and should be kept during the engine s first working hours Thereafter the carburettor should be fine tuned The default setting is H 1 revolution open L 1 revolution open Fine adjustment Fine adjustment of the carburettor should be carried out after the engine has been run in e The air filter should be clean and the cylinder cover fitted when all adjustments are made First adjust the L needle then the H needle and finally the idling speed s T Screw Idling speed 2 800 rpm e Since the ignition system is limited in terms of rom the pre programmed fast idle speed 12 500 13
26. e from the holder A Remove both bolts B Loosen the short circuit cable C from the ignition module Remove the generator D that supplies power to the heated handles 11 2 Electrical system Drive dogs Drive dogs Remove the bolts The drive dogs can be easily replaced if Remove the hooks and the springs to they are damaged replace them Remove the bolts the hooks and the Mind the washer A so as not to lose it springs Replace damaged parts Mind the washer A so as not to lose it Assemble in the reverse order Replace damaged parts Assemble in the reverse order Check that the hooks can be turned freely when the bolts are tight 502 50 18 01 Assembly Assembly Check the key groove in the crankshaft Check that the key groove in the and key in the flywheel If damaged the crankshaft is not damaged If it is the components must be replaced crankshaft must be replaced Attach the ignition module and then the Attach the ignition module and make flywheel sure the short circuit cable is not Check the air gap see page 9 trapped Check that the key in the flywheel is not damaged If it is the flywheel must be replaced Attach the flywheel Check the air gap see page 9 502 51 34 02 Heated handles A The heating element in the handles consists of ceramic plates These are self regulat ing with regard to temperature When temperature increases the resistance in the elements lowers a
27. e it easier to draw the cables to the new heating element back through the handle 1 black 2 blue Remove the bolt that holds the left grip on the handle Pull out handle from the handlebars and then the cables carefully and one at a time so that the steel wire does not loosen from the cables The heating element is located in a pocket in the outside of the handle Use flat nose pliers to pull out the heating element from the handle NOTE Do not pull the cables or their connections Connections can be easily broken Assemble in the reverse order as set out for dismantling Wiring diagram LH Lefthandle RH Throttle HC Heaterswitch TT Triplecontact IM Ignition module SC Short circuit switch Gen Generator Blu blue BI black Re red BI Blu black blue Use a universal tool when checking wiring and heating elements Set the instrument to measure resistance to check for open circuits 13 Electrical system Fuel system Contents Air filter Tank venting Fuel filter Fuel pump Carburettor Assembly Carburettor settings Throttle In addition to the fuel tank and carburettor the fuel system consists of the air filter fuel filter and tank venting Allthese components interact so that the engine receives Fuel system the optimal mixture of fuel and air to make it as efficient as possible Very small deviations in the carburettor setting or a blocked air fil
28. her parts Assemble the carburettor and the other parts in the reverse order as set out for dismantling Analysis and actions Experience tells us that piston or cylinder failure due to manufacturing errors are extremely rare The reason is usually due to other factors which is evident from the following Note the reasons for the breakdown repair the damage and take the actions required to prevent the same thing happening again Insufficient lubrication The piston has small to medium size score marks usually in front of the exhaust port In extreme cases heat development can be so great that material from the piston smears along the piston skirt and even in the cylinder bore Generally the piston ring is undamaged and moves freely in the ring groove There can also be scores on the inlet side of the piston Small to medium size scores primarily in the middle of the exhaust port Cause Action e Incorrect carburettor setting Check and change the carburettor Recommended max speed ex setting ceeded e Incorrect oil mixture in the fuel Change the fuel e Too low octane fuel Change to a higher octane petrol 45 Cylinder and piston Medium to deep scores along the entire piston skirt on the exhaust side Medium to deep scores on the exhaust side The piston ring i
29. ing gasket for example the pump unit does not function and the engine cannot be started Dismantling the carburettor Carefully remove the control dia phragm A and gasket B Check the diaphragm for holes and wear on the pin C Replace the diaphragm if required Connect pressure tester 531 03 06 23 to the fuel hose nipple Lower the carburettor in a vessel with petrol in order to discover any leaks more easily Test the pressure at 50 kPa No leakage is permitted gt T TI T I p ae Fuel system In the event of leakage remove the needle valve Check the needle valve and the lever arm for damage or wear Replace damaged components with new ones Remove the pump diaphragm Check the diaphragm for damage Remove the fuel screen and clean it or attach a new one 3 In the event of leakage remove the needle valve Loosen the bolt and remove the lever arm axle needle valve and spring Check the needle valve for damage on the tip and in the lever arm groove Check the lever arm for damage to the groove for the needle valve and wear on the mounting points towards the control diaphragm Replace damaged components with new ones Remove the bolt holding the cover over the pump diaphragm Lift off the cover A the gasket B and the diaphragm C Check the diaphragm for damage to the valve tongues If the valve tongues are bent the pump will not function i
30. n a satisfactory manner Hold it up to a light as well to discover any holes in the material Carefully remove the fuel screen D using a needle for example Clean or replace the fuel screen NOTE During assembly the pump diaphragm should lie closest to the carburettor housing 21 22 Fuel system Dismantle the main jet A and the plug B Check valves and dampers for wear Replace if required Remove the movement limiters from the jet needles using flat nose pliers Unscrew the jet needles Do not lose the small washers A Lift off the plastic and rubber guides NOTE Note how the jets are positioned For example the H needle is a little shorter than the L needle Press out the main jet A with a suitable punch Remove the plug B Carefully drill a small hole 2 mm in the plug and pry it up with a pointed object Remove the valves and dampers If these components are worn idling is disrupted Always replace the valves and dampers at the same time Fuel system 3 Assembling the carburettor Assembling the carburettor Blow the carburettor housing clean e Blow all channels in the carburettor Fit a new plug compartment clean Fit a new main jet Mount a new plug Use a suitable punch to get a completely tight seal e Press in a new main jet e Mount the valves and dampers Tip Any numbers on the valves should be able to be re
31. n monoxide content brought about the new engine design Environment degradation is reduced through decreasing the amount of unburned gases flushing losses in the exhaust fumes Comparisons between an E Tech engine and an older engine design show that the CO content has been halved and the hydrocarbons and nitrous oxide contents have been reduced by close to 70 In addition a powerful increase in output is gained What makes the E Tech engine design Unique is not a specific design solution but rather several solutions interacting to reduce flushing losses in the engine The carburettor s job is to mix the air and fuel in the right proportions to give a combustible mixture irrespective of the speed and workload The carburet tor s adjustable needles have been fitted with movement limiters to prevent the engine from being run with a too rich fuel air mixture Also see the Fuel system chapter 57 58 Tools ae OY SM Contents Starter Electrical system Fuel system Centrifugal clutch Angle gear Cylinder and piston Crankshaft and crankcase Workshop equipment 60 60 60 60 61 61 61 61 59 8 List of tools OD m fuel sys 502 50 18 01 502 51 91 01 531 00 60 76 531 00 48 63 502 21 58 01 502 71 13 01 502 50 83 01 502 54 15 01 cig x 0 3 502 51 34 02 501 60 02 03 502 50 06 01 502 54 15 01 502 51 94 01 J List of tools Se 502 50 65 01 502
32. nd so does the temperature So no separate thermostat is needed Remove the throttle from the handle Remove the throttle from the handle In order to have access the bolt that See also chapter 3 Throttle emo circuit breaker must be removed to the bolt A that holds the throttle and reach the electrical cables cover B and the heater switch must first be removed 2 bolts 502 50 18 01 The heating element in the throttle is A heating element is placed in the accessed when the throttle lock is throttle lock for involuntary throttling pushed out of the throttle Press the locking catch from the Pry off the locking catch and lift out the throttle making sure not to lose the heating element spring A Pry off the locking catch B and lift out the heating element C NOTE Do not pry off the heating element before the locking catch has been removed The element can be damaged 12 Electrical system Separate the contacts A A and B B Then extend the cables A and B with approx 90 cm long steel wires attached to the contacts Remove the bolt and pull off the left grip from the handle Pull one cable at a time from the handle Remove the heating element from the handle with a pair of flat nosed pliers 2 Separate the contacts A A and B B Then extend the cables A and B with approx 90 cm long steel wires attached to the contacts This is to mak
33. nt of the exhaust port The ring is weakened by the wear and can be caught in the port causing serious piston damage Exhaust side damaged by a broken piston ring The piston ring parts damage the top section and cause score marks li The guide pin for the piston ring has been Deep irregular grooves caused by a loose _ Irregular grooves on the piston s inlet side pushed up through the top of piston circlip Shown here on the piston s inlet caused by a broken roller retainer side Piston ring guide pin Damage caused by Bearing failure vibrated loose gudgeon pin circlips Failure of the crankshaft bearing or on the A too high engine speed can cause the A too high engine speed can cause the Connecting rod bearing is usually caused by a too high engine speed resulting in the bearing being overloaded or overheat ing This in turn can cause the bearing ends of the piston ring to hammer against gudgeon pin circlips to vibrate The the guide pin when the piston ring moves _circlips are drawn out of their grooves due in its groove The intensive hammering to the vibrations which in turn reduces poli can drive out the pin through the top of the circlips tensioning power The rings rollers or ball to glide instead of rotate the piston causing serious damage also can then become loose and damage the Which can cause the roller or ball retainer to the cylinder piston to break The broken debris can be trappe
34. ough the tank s fill hole 502 50 83 01 3 Impregnate the filter with air filter oil Tip Place the filter in a plastic bag and pour about a tablespoon of air filter oil no 531 00 60 76 into the bag Massage the oil into the air filter Tank venting Tank venting takes place through the fuel cap and needs to be functional for the engine to work Remove the fuel hose from the carburettor and empty the fuel from the tank Connect the fuel hose to pressure tester no 531 03 06 23 e Pump up a pressure and vacuum of 50 kPa 0 5 bar in the tank e The pressure should sink to 20 kPa or return to normal pressure within 45 seconds The fuel cap can be taken apart for cleaning Use a screwdriver and prise off the housing A that contains a rubber diaphragm B anda filter C Knock the housing against a tabletop so that the cover D over the dia phragm falls off Blow the filter C clean and the sintered filter E with compressed air and mount the fuel cap in the reverse order to how it was disassembled Make sure that the flat surface on the cover D is turned towards the dia phragm Fuel filter The fuel hose in the tank contains a fuel filter It is accessible through the fill hole Pull out the filter with your fingers or with help of tool 502 50 83 01 NOTE The fuel filter can snag under the shaft bushing in the tank With the aid of a long screwdriver loosen the filte
35. p and push out the bearings with a suitable punch and hammer Dismantling is easier if the clutch housing is heated to about 110 C Assemble in the reverse order as set out for dismantling 35 36 Angle gear Contents Dismantling Assembly Shaft The angle gear has two purposes The first is to gear down the engine s high speed to better suit the lower speed a saw blade or trimmer requires to work efficiently Angle gear Second the angle gear contributes to the saw opera tor s working stance so that it is comfortable and at the same time efficient The power from the engine via the drive axle shall in other words be angled so that the cutting equipment works parallel to the ground 38 Dismantling Remove the cutting equipment and guard Then loosen the bolts holding the angle gear against the shaft Remove the angle gear from the shaft Remove the circlip and washer on the output axle Remove the large circlip from the input axle Dismantling First remove the cutting equipment saw blade trimmer etc and guard Then loosen the bolts holding the angle gear against the shaft Remove the angle gear from the shaft Use a screwdriver if necessary to separate the mechanical joint Remove the circlip on the output axle using circlip pliers Lift off the washer from the sealing ring Remove the large circlip from the input axle NOTE Let the small circlip
36. ppears With deep seizure score marks the piston and cylinder should be replaced Surface coating in the cylinder bore worn out primarily at Replace the cylinder and piston the top of the cylinder The piston shows signs of seizure score marks Carefully polish the damaged area using a fine file of fine grade emery cloth Before the piston is refitted the cylinder should be polished as above With deep score marks the piston and cylinder should be replaced Piston ring burnt in its groove Carefully loosen the piston rings and clean the groove well before refitting Carbon deposits in the groove impair the important heat transfer between the piston and cylinder NOTE Be careful with the lower edge of the piston ring groove If this is damaged or if carbon deposits remain the compression pressure can leak through Check the wear on the piston ring by placing it in the lower part of the cylinder Bolts much too tight in the aluminium material Position a suitable punch on the bolt head and give a few sharp knocks with a hammer If the bolt still does not loosen repeat the procedure 49 6 Cylinder and piston Wear tolerances Cylinder bore Piston ring gap Piston ring groove Piston ring play When the surface coating is Max 1 0 mm with the piston Max 1 6 mm Clean the groove Max 0 15 mm Clean the groove worn and aluminium appears ring inserted in the lower part before checking the measure before checking the measure
37. r Do not pull on the hose since it can easily be pulled from the filter 17 18 Fuel system Clean the filter externally if it is not too dirty Replace the filter if required Fuel pump The fuel pump facilitates cold starts The pump cannot be repaired and must be replaced if it stops working Note how the fuel hoses are connected to simplify assembly Carburettor Dismantling Blow clean the carburettor compartment Loosen the bolts A and remove the nuts B Remove the fuel hose C and fold the filter holder aside If the filter is not too dirty its surface can be cleaned with a brush Otherwise it must be replaced Check the fuel hose for cracks and leaks Make sure that the filter s connection neck is inserted as far as possible into the fuel hose and that the O ring is sufficiently tight so that the filter cannot slide off the tube Fuel pump The fuel pump has the task of facilitat ing the start of the engine when cold The pump fills the carburettor with fuel before attempting to start the engine This also prevents vapour bubbles from blocking the narrow fuel channels If the pump does not work it must be replaced Note how the fuel hoses are connected to simplify assembly Carburettor Dismantling 1 Remove the carburettor cover and blow the carburettor compartment clean with compressed air 2 Loosen the bolts A 3 Remove the nuts B 4 Remove the fuel ho
38. rn e D 531 00 48 63 halves of the throttle 502 50 18 01 Carburettor adjustment 345RX FX Adjusting the H needle 1 Mount the Trimmy Fix 4 wires and use 3 3 mm smooth cord The cord length should be 160 mm measured from the end of the cord to the cord bushing on the trimmer head 2 Run the engine warm for about 5 minutes Turn the H needle so that the highest speed is attained 4 Reduce the speed by 400 rpm by turning the H needle anticlockwise Mount the plastic sleeve on the H needle so that it cannot be turned anticlockwise 5 Then increase the speed by 200 rpm by turning the H needle clockwise R NOTE If the cutting equipment rotates while idling the T screw should be turned anticlockwise until it stops rotating Carburettor needles with Zama caps 531 03 03 98 Throttle Throttle Disassemble the cable protector B Remove the bolt A and cable protec the cover D and the throttle from the tor B handle Remove the two bolts C and the cover Remove the bolts and separate the two D Remove the bolt E that attaches the throttle to the handle and remove the throttle Remove the bolts and separate the two halves of the throttle 27 Fuel system 28 Remove the bolt A and remove the throttle from the handle Remove bolts B and C Separate the halves of the throttle Check for wear on pins A and B Replace the throttle control
39. s stuck in the groove Black discoloration under the piston ring due to blow by 46 The piston ring starts to stick or is completely stuck in its groove and has therefore not been able to seal against the cylinder wall which has resulted in further intensive temperature increases in the piston Seizure scores along the entire piston skirt on the inlet and exhaust sides Cause e Incorrect oil mixture in the fuel e Too low octane fuel e Air leaks Cracked fuel hose Leaking inlet gaskets Cracked distance piece or inlet manifold e Air leakage in engine body Leaking crankshaft seals Leaking cylinder and crankcase gaskets e Poor maintenance Dirty cooling fins on the cylinder Blocked air intake on the starter Blocked spark arrestor mesh in the muffler Action Change to a fuel with the correct oil mixture Change to a higher octane petrol Replace damaged parts Replace leaking gaskets and shaft seals Clean the cooling fins and air intake Clean or replace the spark arrestor mesh For the best results we recommend Husqvarna two stroke oil or ready mixed fuel that is specially developed for air cooled two stroke engines Mixing ratio 1 50 2 If Husqvarna two stroke oil is not available another good quality two stroke oil can be used Mixing ratio 1 33 3 or 1 25 4 Piston scoring caused by heavy carbon deposits Too heavy carbon depositing can cause damage similar
40. s the name implies it works according to a reversed situation when the cutting equipment jams centrifugal principle Thereby preventing abnormal load changes on the This means the clutch s friction shoes are thrown out crankshaft wards towards the clutch drum at a certain engine speed The engagement speed has been carefully tested so When the friction against the drum is sufficiently great it that the engine can idle without the cutting equip drives the drive shaft at the same speed as the engine ment s drive shaft rotating Dismantling Dismantling Dismantle the cable protector loosen The clutch is located between the fuel bolts A and B tank and the engine In order to be accessible the tank and handle holder must be moved forward on the shaft 1 Dismantle the cable protector 2 Loosen bolts A and B Move the fuel tank so far forward that 3 Move the fuel tank so far forward the fuel hoses C and D can be that the fuel hose C becomes removed accessible Move the O ring back and remove the hose from the nipple Also remove the fuel hose D from the nipple on the tank Remove the 4 bolts holding the clutch Move the fuel tank further forward and cover remove the 4 bolts holding the clutch Dismantle the vibration dampers for cover to the engine better access Remove the vibration dampers from their plugs in order to facilitate disman tling 502 21 58 01 32 Centrifugal clutch Di
41. se C from the carburettor and the filter holder 505 38 13 08 502 50 18 01 Move the fuel tank so far forward that the fuel hoses C and D can be removed 5 Move the fuel tank so far forward that the fuel hose C becomes accessible Move the O ring back and remove the hose from the nipple Also remove the fuel hose D from the nipple on the tank Fuel system Remove the throttle cable and fuel hose from the carburettor Remove the carburettor The carburettor is made by Zama Design function and servicing corre spond with the Walbro carburettor Default carburettor settings H 1 revolution open L 1 revolution open The carburettor needles are fitted with movement limiters caps The carburettor s design The carburettor can be divided into three different functional units the metering unit the blending unit and the pump unit The metering unit The needles and the fuel control functions are located here The blending unit Fuel and air are mixed here 3 Remove the throttle cable from the carburettor s lever arm using flat nose pliers Pull off the fuel hose and remove the carburettor Tip Open the fuel cap to avoid fuel spillage caused by any excess pressure Attach the fuel hose to the return nipple The carburettor is made by Zama It has the same design and function as the Walbro carburettor which means that servicing is also carried out in
42. smantle the clutch from the crank shaft 502 54 15 01 Remove the 3 bolts and separate the clutch Twist apart the clutch Clean and inspect the different parts with regard to wear or other damage 4 Replace the spark plug with piston stop no 502 54 15 01 Move the engine body to the side so that the clutch becomes accessible Unscrew the clutch from the crankshaft Fix the clutch in a vice and remove the 3 bolts Lift off the front cover plate and the clutch shoes NOTE Do not lose the sleeve bearings found in the clutch shoes Twist apart the clutch Clean and inspect the different parts with regard to wear or other damage Wear on the clutch shoes must not be greater than shown in the illustration Check the play in the sleeve bearings in the clutch shoes and the wear on the springs by the fastening hooks 33 Centrifugal clutch Assembly Temporarily place the clutch shoes on the driving disc and loosely tighten the bolts Pry out the shoes and hook one spring to each shoe from underneath Get in the clutch shoes as far as possible and hook the springs to the adjacent clutch shoe Remove the bolts and mount the cover plate Fit the clutch to the crankshaft and the remaining parts in the reverse order as set out for dismantling Clutch drum Dismantle the clutch housing and the clutch drum and drive axle from the shaft Unscrew the clutch drum from the drive a
43. sure that it is not damaged by such things as the collars and splines on an axle Use tape or a conical bushing as protection It is important that the sealing ring is turned correctly in order for it to function as intended NOTE Material damage may occur if the instructions are not followed Starter Contents Dismantling Assembly Replacing the drive dogs 1 Starter WARNING A N Protective glasses should be worn when working on the starter to avoid injury to the eyes if for some reason the return spring should fly out Dismantling Remove the starter from the engine 502 50 18 01 Loosen the spring tension Remove the bolt in the centre of the starter pulley and remove the starter pulley Dismantling Remove the 4 bolts and lift off the starter The cylinder cover does not need to be loosened or detached Loosen the spring tension Pull out the starter cord about 30 cm Brake the starter pulley with your thumb and lift the cord as illustrated Let the starter pulley rotate backwards slowly Remove the bolt in the centre of the starter pulley Lift the starter pulley carefully from the starter cover Starter 1 Remove the spring cassette Remove the two bolts holding the spring cassette and remove the cassette for replacement if necessary WARNING Wear protective glasses The return spring can fly out and cause personal injury if improperly handled Assembly
44. tension With the cord completely pulled out the cord pulley should be able to be turned at least another half revolution Mount the starter onto the engine Pull out the starter cord a little Place the starter in position and release the starter cord at the same time Check that the ignition cable is not trapped see arrow Check that the drive dogs grip the starter pulley in the correct way Tighten the bolts Replacing the drive dogs See chapter 2 Ignition system Electrical system Contents Checking the ignition spark Replacing the spark plug cover Dismantling Drive dogs Assembly Heated handles 10 11 12 12 Electrical system The engine is equipped with an electronic ignition system completely without moving parts Conse quently a faulty component cannot be repaired but must be replaced by a new component The spark in an electronic ignition system has a very short burn time and can therefore be interpreted as weak and can be difficult to see while troubleshooting ae _ AS gt N 9 Checking the ignition spark Clean the electrodes and check the electrode gap 502 51 91 01 If the electrodes are worn more than 50 the spark plug should be changed Check if a spark occurs when attempt ing to start Test with test spark plug no 502 71 13 01 if no spark is seen 502 71 13 01 Checking the ignition spark Remove the spark plug and
45. ter have a large effect on the running and efficiency of the engine 16 Air filter Remove the air filter holder Separate the filter halves and clean the nylon filter in warm soapy water The R variant has a foam rubber filter The carburettor can come from several different manufacturers on our models but the function and repair methods are essentially the same Air filter Dismantle the cover A and remove the air filter B The nylon filter comes in two models The standard filter has a mesh size of 80u There is also a 44y unit available There is also a flock filter also as an accessory The air filter comes apart Separate the two halves with a screwdriver Clean the filter in warm soapy water If the filter fabric is damaged the entire filter should be changed The R variant has a foam rubber filter A N WARNING Do not clean not the filter with petrol Hazardous NOTE Do not blow the filter clean with compressed air It can be damaged Ensure that the filter is dry before refitting it Remove the foam rubber filter and clean it in warm soapy water Remove the foam rubber filter and clean it in warm soapy water Fuel system Impregnate the filter with air filter oil 531 00 60 76 Tank venting Check that the tank venting valve works correctly Replace the fuel cap if the valve is faulty Fuel filter The fuel filter can be removed thr
46. that the air hole in the cover is open and screw the cover on Assembly Slide the carburettor into place Connect the fuel hose A to the carburettor Connect the fuel hose B to the carburettor and make sure that it is in the groove C Place the filter holder in place and make sure that the fuel hose D is under the carburettor and is not pinched Connect the throttle cable E to the carburettor Screw down the filter holder and attach the air filter NOTE Check carefully that the fuel hoses are not bent or pinched when the fuel tank is pushed back into place against the engine body Fuel system 3 Carburettor settings WARNING When testing the engine in connection with carburettor adjustment the clutch and clutch cover must be mounted together with the shaft and angle gear under all circumstances Otherwise there is a risk of the clutch becoming loose resulting in serious personal injury Function The carburettor has the task of supplying a combustible fuel air mixture to the cylinder The amount of this mixture is controlled by the throttle The mixture s composition of fuel and air is controlled by means of the adjustable H and L needles The needles must be correctly adjusted in order for the engine to give maximum power at different speeds run steadily while idling and to react quickly when accelerating The setting of the carburettor can vary a little depending on the humi
47. the same way The lever arm should lie flush with the carburettor housing s contact face Default carburettor settings H 1 revolution open L 1 revolution open The carburettor needles are fitted with movement limiters caps The carburettor s design The carburettor can be divided into three different functional units the metering unit the blending unit and the pump unit The metering unit The needles A and the fuel control functions are located here The needle valve B and control diaphragm C are vital to the carburet tor s function The blending unit In this section of the carburettor fuel and air are mixed in the proper propor tions The choke and throttle valves are placed here In the middle of the venturi narrowest part of the throughput the main jet D is found 19 Fuel system cs cr GE FASERN As gt 4 yWwr_a lt DOS ANOS LLL D AL N f 20 The pump unit Pumps fuel from the tank to the carbu rettor Dismantling the carburettor Remove the control diaphragm and check for damage Replace if required Pressure test the metering unit 531 03 06 23 The pump unit This is where the pump diaphragm E that pumps fuel from the tank to the carburettor s measuring unit is found The diaphragm is affected by pressure variations in the engine s crankcase via an impulse channel F If the channel is blocked by grease or a wrongly fac
48. to that caused by insuffi cient lubrication However the piston skirt has a darker colour caused by the hot combustion gases that are blown past the piston This type of piston damage starts at the exhaust port where carbon deposits can become loose and get trapped between the piston and the cylinder wall Typical for this type of piston damage is brown or black discoloration of the piston skirt Cause e Wrong type of two stroke oil or petrol e Incorrect oil mixture in the petrol e Incorrect carburettor setting Action Change the fuel Change to a fuel with the correct oil mixture Correct the carburettor setting Cylinder and piston 6 Piston damage caused by a too high engine speed Typical damage associated with a too high engine speed includes broken piston rings broken circlip on the gudgeon pin faulty bearings or that the guide pin for the Mii piston ring has become loose Piston ring breakage A too lean carburettor setting results in a too high speed and a high piston temperature If the piston temperature rises above the normal working temperature the piston ring can seize in its groove consequently it will not sit deep enough in its groove The edges of the piston ring can then hit the top edge of the exhaust port and be smashed and also cause piston damage A too high engine speed can also cause rapid wear to the piston ring and play in the piston ring groove primarily in fro
49. ts exposed to most strain in the engine They must the utmost importance It is therefore recommended withstand for example high speeds large tempera that the cylinder and the area around it be thoroughly ture swings and high pressure Moreover they must cleaned before being dismantled from the crankcase be resistant to wear Despite these tough working conditions major piston and cylinder failure is rela tively uncommon The reasons for this include new coatings in the cylinder bore new types of oil and grease and refined manufacturing techniques Dismantling Dismantle the following components to make the cylinder accessible Starter cylinder cover muffler guard muffler and spark plug oe gr li W NOTE The throttle need not be removed to dismantle the cylinder and piston S y Loosen the clamp A and unscrew the bolt a good distance to facilitate the coming assembly so that the clamp can be turned around the inlet manifold without affecting the cylinder Then loosen the 4 bolts holding the cylinder Carefully lift out the cylinder by twisting is backwards and forwards until it loosens from the inlet manifold Make sure that no dirt enters the crankcase Use a rag to cover the crankcase opening under the piston 502 50 18 01 Remove the circlips from the gudgeon Using long nose pliers remove the pin gudgeon pin circlips Keep your thumb over the circlip to prevent it from flying out
50. xle 502 52 16 02 502 11 46 03 Assembly Temporarily place the clutch shoes on the driving disc and loosely tighten the bolts NOTE The bevelled edge of the shoes should be facing outwards towards the cover plate Pry out the shoes and hook one spring to each shoe from underneath Fold in the clutch shoes as far as possible and hook the springs to the adjacent clutch shoe Use a small screwdriver or flat nosed pliers NOTE Make sure that the spring eye is pressed into the correct position Remove the bolts and put the cover plate in place Tighten the bolts fit the clutch to the crankshaft and the remaining parts in the reverse order as set out for dismantling Clutch drum Separate the engine body and shaft as described previously Loosen the bolts holding the clutch housing against the shaft Remove the clutch housing and drive axle from the shaft Unscrew the clutch drum from the drive axle NOTE Avoid fixing the drive axle in a vice Marks can form on the axle even if protective jaws are used This in turn leads to damage on the plastic insert in the shaft Use tools 502 52 16 02 and 502 11 46 03 Check the clutch drum for wear The internal diameter must not exceed 70 0mm Centrifugal clutch Change the bearings in the clutch housing if necessary 505 38 17 09 4 Change the bearings in the clutch housing if necessary Remove the circli
51. y out adjustment when replacing needles or the entire carburettor the engine must be under load This is achieved by fitting a Trimmy Fix with the specified length and diameter of trimmer cord Consequently the stated speed will be much lower than with normal carburettor adjustment when the engine may run freely After replacing the needles or the entire carburettor on a CARB EPA approved engine adjustment must be carried out according to the instructions below The combiguard or trim guard must be fitted when adjusting the H needle Fuel system 3 Carburettor adjustment 345RX FX Adjusting the L needle 1 Mount the Trimmy Fix 4 wires and use 3 3 mm smooth cord The cord length should be 160 mm measured from the end of the cord to the cord bushing on the trimmer head Run the engine warm for about 5 minutes Turn the L needle so that the highest speed is attained If the speed exceeds 3 700 rpm reduce it with the aid of the idling speed s T screw T and a carry out a new adjustment in accordance with point 3 5 Then turn the L needle anticlockwise so that the speed drops by 300 rpm 6 Then adjust the idling speed to 2 800 rpm by turning the T SCrew 7 When mounting the plastic sleeve on the L needle the needle is turned a quarter turn anticlockwise once the optimal setting has been made and the plastic sleeve is mounted so that the needle cannot be turned anticlockwise Then turn the L needle back a quarter tu
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